It is ironic that 25 years after the introduction of
the first generation CD player by the Sony/Philips consortium a groundswell of
designs has emerged that challenge one of the mediumís fundamental engineering
assumptions. It had been considered a given that an anti-imaging filter is
necessary to remove the ultrasonics generated during the digital to analog
conversion process. Recall that the earliest players used multi-bit DAC chips
followed by analog "brick wall" filters designed to steeply attenuate the image
spectra above 22 kHz. While the specs looked good on paper, the promise of "perfect
sound forever" turned sour quickly as a chorus of complains echoed a common
theme: bright, fatiguing sound that ultimately resulted in digititis Ė an
allergic reaction to digital sound. The establishmentís initial reaction was
to blame the messenger; namely, digital masters were said to be the culprit. I
recall listening to J. Gordon Holtís Sony CDP-101, the first kid on the block
with a CD player. This one being a seminal first-generation player, and a gift
from the marketing folks at Sony. Out of a stack of some 30 CDs, only a couple
managed to sound decent. Slowly, the real problem was recognized to be the brick
wall filter and sure enough second-generation players took advantage of evolving
digital signal processing technology and incorporated digital oversampling
filters positioned prior to the multi-bit DAC. I have no preconceived bias
against digital filters; they neither generate new information nor improve
resolution, but they do allow the use of much gentler analog filters, which are
audibly benign.

Now, just when it appeared that the digital ship had righted itself, a new "dark
age" was spawned with the advent of the single-bit sigma-delta converter. Author
Ken Pohlmann (The Compact Disc Handbook) gives an excellent analogy of
how such a chip works. He likens it to a light switch operating at a high
frequency. The two extreme amplitude states are off and on, but also any
intermediate level can be achieved by toggling the switch off and on rapidly at
a given frequency. The single-bit DAC was seen as offering the potential of
increased linearity relative to the older R2R type at lower cost while obviating
the need for factory calibration. In contrast, the R2R DAC uses an onboard
voltage-divider resistor network or ladder capable of generating 65,536 voltage
values. Each bit in a 16-bit data word enters the ladder through a switch. The
most significant bit (MSB) enters the ladder at the top, while the least
significant bit (LSB) is assigned the last section in the resistor network. A
data zero keep the corresponding switch open, while each 1 closes a switch and
allows that bit to contribute to the overall output voltage. Granted, the LSB is
difficult to maintain in calibration, but the output is free of the RF switching
noise that afflicts the sigma-delta type, which requires sophisticated digital
noise shaping techniques to work at all. Since noise cannot be destroyed, noise
shaping merely shifts the noise: reducing noise within the audible bandwidth
while increasing it at higher frequencies. More recent low-bit sigma-delta
designs improve the situation somewhat but fail to change the bottom line:
improving linearity at the cost of increasing high-frequency noise is a poor
tradeoff.

In my experience, designs based on the sigma-delta chip tend to sound bright
and/or lack convincing timbre accuracy. Altmann Micro Machinesí progenitor,
Charles Altmann, is much more empathic about this issue. In his opinion, there
is no music possible with sigma-delta DACs. In his experience R2R chips are the
only way to achieve a listenable sound quality. However, the type of R2R chip
used, he feels, is of far less importance than the skill of the designer. While
from a technical standpoint he appreciates R2R type DACs such as the Burr-Brown
PCM1704 (true 24-bit noise-free resolution), they are not necessarily well
suited to zero oversampling applications. He believes that he has been able to
push the Philips TDA1543 dual 16-bit DAC to incredible results. Incidentally, by
virtue of its single +5V voltage rail, it is compatible with battery power
supplies. Some might consider the TDA1543 as a relic from a bygone era, but its
low-cost, potential for good sound and compatibility with battery power have
made it a favorite with many designers. In fact, three of the four DACs reviewed
herein use this particular chip.

So Are Anti-Imaging Filters Really Needed?Well, yes, if using a sigma-delta DAC; the noise shaping employed makes
anti-imaging filtration mandatory. However, the answer would appear to be a
resounding No in the case of an R2R DAC. The definitive means of settling such
questions is, to my mind, the time-honored listening test. It was the inimitable
Harry Olson, who elucidated this principle many ears ago in the form "the ear is
the final arbiter in audio matters." There is not necessarily a direct
relationship between what is measured and what is perceived. Al Bregman, author
of Auditory Scene Analysis: The Perceptual Organization of Sound (MIT
Press, 1994) relates that in about 1969, a few years after he had arrived at
McGill University as an assistant professor in cognitive psychology, he became
involved in an experiment on auditory perception in which the signal was a rapid
sequence of unrelated sounds. The realization that the perceived sequence was
not the actual sequence of sounds launched him into a life-long study of
auditory perception. Unfortunately, the scope and spectrum analyzer have
displaced the auditory system in the mistaken belief that perceptual pleasure is
an inevitable consequence of engineering excellence.

It was the golden-eared Peter Qvortrup at Audio Note UK who first dared to
listen directly to an R2Rís DAC output Ė minus analog filters and what he
refers to as "digital trickery." What Peter discovered is a sound quality that
is much more closely akin to the vinyl experience. In my experience, zero
oversampling gives the impression of a more believable soundstage. The spatial
impression in terms of depth and width perspectives is typically better defined
relative to oversampling designs. It is as though the auditory system is
presented with a better set of cues with which to synthesize a 3-D impression of
the auditory stream. Perhaps the Gestalt psychology principle of closure is at
work here. This is a mechanism for dealing with missing information, a means, if
you will of connecting the dots (to use a visual analogy). An example given by
Al Bregman is that of a soft sound being masked or drowned out by a louder one.
If the softer sound can be heard both before and after a burst of the louder
sound, it can be perceived to continue behind the louder sound Ė even if it is
physically removed while the loud sound is being played.

Welcome to the natural voicing of zero oversampling. What a breath of fresh
air! Gone is the endemic brightness of early CD players and sigma-delta
converters and its associated sensory overload. Yet, the relative paucity of
zero oversampling designs makes you wonder whether most DAC designers spend more
time measuring than listening.

What about the ultrasonic energy present at the output of a zero oversampling
DAC? Is it likely to overload or generate distortion products in the associated
analog chain? While that is always a possibility with high-frequency test
signals, there is no evidence that this is at all an issue with music program
material. The proof is in the listening.

The Jitter GameI am not suggesting that all it takes to make an excellent sounding DAC is to
assemble a decent R2R DAC and omit the analog and digital anti-imaging filters.
Other important design factors are the DAC chipís operating point, power
supply, output buffer and analog gain stages, and the designerís experience in
integrating digital and analog circuit designs. And even when all of these
factors are properly addressed there still remains the issue of jitter, time
base variations that cause data to arrive at the DAC chip slightly out of sync
with the clock cycle. It is understood that large amounts of jitter, in the
range of 100 to 200 nanoseconds (nS), which might occur when a disc is read by a
substandard laser pickup could result in data errors. Studies have shown,
however, that even cheap transports are capable of correctly retrieving all of
the encoded data. Of greater interest are the distortion products generated by
jitter at the DACís output. There is some controversy over the audibility of
low-levels of jitter and its actual threshold of audibility. Some studies have
suggested thresholds of 20 to 30 nS with selected test signals and even higher
limits of detection with music signal because of masking effects. However, the
experience of many audiophiles suggests a much lower threshold.

If we assume that 20 nS is about the correct threshold for the audibility of
jitter, then any player that, for example, deploys the ubiquitous Crystal
Semiconductor CS8413/14 receiver chip should handily eliminate the audible
effects of jitter. The primary functions of this chip are to recover and decode
the audio data from the S/PDIF digital data stream. A low-jitter clock is
provided onboard that uses a phase-locked loop and a voltage-controlled
oscillator. Jitter is reduced at the output to typically 200 picoseconds (pS) or
0.2 nS. Thatís a factor of 100 lower than the threshold of audibility claimed
by some. Yet, many audiophiles have experienced an increase in clarity and speed
with decreasing levels of jitter well below 200 pS. Therefore, it can be safely
stated that any design whose entire jitter reduction is dependent on
an-of-the-shelf receiver chip cannot possibly offer state-of-the-art
performance.

The TransportIn
order to keep the competition on an equal footing, the same CD transport was
used for all of the listening tests. The 47 Laboratory model 4716 ($1980) has
been around for several years and represents a good value. As with the entire
Shigaraki line, emphasis is placed on vibration control. The chassis is anchored
to a thick ceramic slab to control the time signature of resonant energy. It is
sonically superior to a mass-market transport, though in all honesty much of the
overall sound quality of a digital front end can be attributed to the DAC. For
example, when used together with the 4715 DAC, the 4716 in my estimation
contributed only about 25% of the overall sound quality.

The Scott Nixon Audio Tube Dac+Scott
Nixon is best known for his line of affordable audio kits. The TubeDac+ is
however only available fully assembled ($475). It ships with either a
wall-mounted transformer or with the 3Xac 12VAC/3A toroidal power supply
($125.00 - less 10 percent when ordered with the TubeDac+), which is how my
review sample was configured. The chip set consists of the Crystal CS8412
receiver and the Philips TDA1543 DAC. The output stage features a 6DJ8/6922 tube
buffer, which lowers the output impedance and allows the Dac+ to mate with
fairly low input impedance line stages and integrated amplifiers (>20 kOhm).
There is also a passive "anti-sinc" filter that can be switched in and out. I
assume that this corresponds to a first-order anti-imaging analog filter. Note
that the unit inverts polarity. This, of course can be taken care of by simply
reversing leads at the amplifier/speaker interface. But it would be very useful
to have a means of inverting polarity on the fly so as to be able to check for
best sounding polarity during playback. This is an issue with multi-track
recordings, where the odds of correct polarity are only 50%. Matters are
actually more complicated, because some tracks may be in phase, while others are
out of phase. Thus, it usually pays to check for best sounding polarity setting
album-by-album or even track-by-track.

Right out of the box, the TubeDac+ sounded significantly substandard. Even
after an extended break-in, the sound was still so grainy and lifeless that I
decided to return the unit to Scott Nixon for a checkup. Scottís finding was
that he DAC chip was clipping a bit and THD was well over 1 percent.
Apparently he has only had a handful of the chips do this, but usually within
the first hour of burn in. The fix consisted of changing the fixed 'vref'
resistor to a trim pot to precisely balance out the waveform.

Back from its visit to the doctorís office, the TubeDac+ sounded much
improved. Sonically, its calling card is a smooth, easy-to-listen-to
presentation with a slightly romantic and prominent midrange. The residual level
of midrange grain was a function of the type of 6922 used. Be sure to avoid any
of the Sovtek variants. Siemens Gold pin and Bugle Boys worked best. Keep in
mind that the buffer stage is operated at exceedingly low B+ voltage. That
avoids the need for and the cost of a high-voltage supply, but the downside is
that the operating point is constrained to a non-linear range of the transfer
curve. It would appear that this design choice is responsible for most of the
unitís sonic shortcomings.

There were problems noted almost immediately at the frequency extremes. The
upper octaves sounded closed-in lacking in air and finesse. That accounted for
the fact that instrumental timbres sounded darker than the real thing. Bass
lines were prominent but lacked adequate pitch definition. Soundstage dimensions
were not fully fleshed out. In particular, the depth perspective was compressed.
Image outlines were broad-brush, lacking the requisite specificity to resolve
massed instruments. I preferred having the "anti-sinc" filter turned off, as it
marginally improved image focus. Veiling of the soundstage-reduced transparency,
which meant that visibility of the inner recesses of a recordingís ambient
space was impaired. Neither was low-level detail resolution on par with the
performance bar set by more expensive DACs. For example, it was difficult to
follow instrumental lines backing a lead vocalist. Background harmonies were
masked to the point of reducing the presentationís clarity. And finally,
dynamic shadings lacked conviction, as transients simply did not rev up as fast
as they should.

47 Laboratory model 4715 DACI
am certain that if 47 Laboratoryís designer, Junji Kimura, proclaimed "Honey,
I shrunk the DAC," it would fail to evoke even a molecule of surprise. After
all, the man has been making a living miniaturizing audio devices and
simplifying the signal path in his quest for the musical experience. Reports of
the demise of the standard CD format (16-bit/44.1kHz) are greatly exaggerated;
thatís the view shared by 47 Laboratory, having discovered that the true
limitations of the format are hardware related. The 4715 ($1480) is part of the
Shigaraki series and follows the true and tried zero oversampling recipe of
deploying the Crystal CS8412 receiver and Philip TDA1543 chip. Current to
voltage conversion at the DAC output is passive without a buffer stage. Note
that the unit inverts signal polarity.

The 4715 has been around for a few years and has garnered several reviews in
the interim. I think that on the basis of musicality, it still holds up well to
the competition. Harmonic textures are smooth and free from electronic glaze and
high-frequency emphasis. Neither is it a detail freak, artificially highlighting
nuances within the tapestry of the music. If I may be permitted a tactless
moment, I would characterize its sound as lacking flash and zing. If offers the
music lover timbre fidelity but without the nervous energy that characterizes
much of digital sound. It is the sort of sound quality that is bound to
disappoint hard-core audiophiles who are into the sound of a recording per se
rather than the music. The tonal balance is reasonably neutral, with just a
slight loss of treble sheen. Bass lines were consistently well defined and well
integrated with the lower midrange. The core of the midrange exhibited a
textural sweetness and purity that has become a hallmark of Kimuraís designs.
This alone was worth the price of admission, as it placed no barriers between
the listener and the soulfulness of the music.

Since the unit lacks a buffer or output gain stage, proper interface matching
becomes essential. A tube preamplifier or line stage, which typically feature
high input impedance appeared to work best. Tube magic also helps the 4715 in
recreating a reasonable soundstage spatial impression. When compared with my
current reference, the Altmann Micro Machinesí Attraction DAC, it became clear
that the 4715 falls short in several respects. A slight veiling of the
soundstage results in a reduction in transparency and loss of low-level detail.
Transient speed is slightly blunted, as is the ability to follow the decay
portion into the background of the recording. It follows that the clarity of the
presentation is not entirely crystalline in nature. Neither are image outlines
as sharply focused as they should be. It would appear that its shortcomings are
due to the limitations imposed by the inherent jitter performance of the CS8412
receiver chip. Unless a designer is willing to look for new means to further
reducing jitter at the output of the receiver chip, state-of-the-art performance
is unattainable.

Bottom line: The 4715ís combination of harmonic sweetness and purity
of expression are noteworthy. A decent performer on all fronts, its most
endearing gift is the ability to involve the listener in the musicís emotional
content. It is not flashy or showy, so itís unlikely to impress hard-core
audiophiles, but otherwise it represents a solid recommendation for the music
lover who simply wants to kick off his shoes and enjoy the music.

Overall rating: 3.5 blue notes out of 5

Audio Note UK DAC1.1x/II SignatureAudio
Note UK, never at a loss for catchy marketing phrases, was first on the scene
with a zero oversampling design. Launched in 1997, the DAC5 heralded the age of
the 1xoversampling Direct from Disc circuit. The Signature version of the
DAC1.1x/II ($2,000) is a relative of that seminal product and probably
represents the best sounding DAC in Audio Noteís affordable tier of DAC
solutions. The Signature version represents an upgraded version of the DAC 1.1x
MkII with the following premium components: Black Gate capacitors, Audio Note
copper foil signal caps, tantalum resistors, and copper-wired digital input
transformer.

Both unbalanced (RCA) and balanced (AES/EBU) connections are provided. Taking
care of the digital data stream is the Crystal CS8414 receiver chip, coupled via
a digital pulse transformer. The converter chip is the Analog Devices AD1865, a
dual 18-bit design offering excellent THD+N and SNR. The AD1865 is a complete,
dual 18-bit DAC. The first four MSBs of each DAC are segmented into 15 elements,
while the 14 LSBs are produced using standard R2R techniques. Both segment and
R2R resistors are laser trimmed to provide extremely low total harmonic
distortion. The AD1865ís onboard high-performance output amplifiers are said
to be capable of fast settling and high slew rate.

An anode follower gain/buffer stage, configured with a single 6DJ8/ECC88/6922
dual triode per channel, is used to keep the output impedance below 2 kOhm. My
review sample was outfitted with a pair of Siemens ECC88 types. When I inquired
about the unitís output signal polarity, I was told that it is phase
inverting. However, to my ears that did not appear to the case, as I obtained
the best sound with the amplifier-speaker interface in-phase.

There was plenty of mojo on display, once I got past the Siemens tubes. My
first impression was that the soundstage was "condomized" Ė that is, wrapped
up in a giant condom. Safe sound is not my idea of listening pleasure. What was
needed was more feeling, less veiling, in a word - more intimacy. It was time
for a bit of tube rolling. Out went the Siemens and in went the Richardson
select new production Bugle Boys. This particular pair had performed extremely
well in other contexts and it did not disappoint in this application. The
presentation became smooth, round, and cohesive in the finest tradition of
vintage tube sound. But most of all, the feeling of Ďbeing thereí was now
much more convincing. The midrange was revved up in terms of transient attack
and immediacy.

The zero oversampling sensation of natural balance was very much in the air.
The lower midrange and upper bass were portrayed with a big tone character,
full-bodied and rhythmically alive, basically giving my 6SN7-based tube line
stage free reign to express its palette of harmonic colors. Think Tennessee
whiskey, Jack Daniel's Old No. 7, which is distilled, then filtered through 10
feet of charcoal, then aged in white oak barrels. The end result is most
definitely mellow. Treble extension was a pleasant surprise, as many zero
oversampling designs sound closed-in, casting a shadow over the soundstage, and
lacking in transient sparkle. Yet, despite its apparent extension, upper octave
brightness and glare were absent in action. Listening fatigue was extremely low
and totally dependent on the character of the recording.

Bass lines were tightly defined. Dynamic nuances were given full scope of
expression. Portrayal of soundstage dimensions was also very good. In
particular, the width perspective was as good as Iíve experienced, extending
linearly from left to right without any bunching at the speakers, and at times
extending beyond the edge of the speakers. As in the case of the 47 Laboratory
model 4715, there was some loss of image focus and low-level detail resolution.
It was not possible to delineate ambient decay fully into the background of the
recording, which translates into a loss in clarity. To my mind, these
shortcomings are most likely attributable to the residual jitter at the output
of the CS8412 receiver chip.

Bottom line: The Audio Note DAC1.1x/II Signature makes for a safe
recommendation for music lovers who have been traumatized by digital sound and
are looking for a safe CD haven. If offers a more kinetic presentation relative
to the 47 Laboratory model 4715, while retaining the latterís zero
oversampling virtues. But be prepared to experiment with tube substitutions.

Overall rating: 3.75 blue notes out of 5

Altmann Micro Machines Attraction DAC

And
now for something completely different; and yes, I did leave the best for last!
What you see is far from the typical DAC in a box. In fact, there is no box. All
components fit neatly onto a small surface-mount circuit board, which is affixed
to a piece of spruce that has been treated for vibration control. The Attraction
DAC is designed to be powered by a single 12V automotive battery. It is part of
AMMís BYOB line Ė that is, Bring Your Own Battery. AMM recommends the Optima
Redtop spill-proof lead-acid battery, which is what I use (model 34). You will
also need a battery charger, but with a current draw of only 200 mA, thereís a
reserve of well over 200 hours of enjoyable listening before re-charging is
required. And battery status is monitored by a blue LED; when it starts dimming
it is your cue to start a re-charge cycle. Every Attraction DAC comes complete
with a gold-plate battery cable and a five years limited warranty.

While
the idea of battery power is not new, it is particularly relevant in the case of
a DAC. For example, power supply voltage fluctuations induce jitter at the
input of an R2R type converter chip, since the reference voltage controls the
firing of the switches at the input to the resistor ladder. This is clearly a
situation where the purest power supply is needed, and the idea of decoupling it
completely from the AC mains represents the right call. No need for power
transformers, rectifiers, filters, and regulators with all of their attendant
noise. Battery supplies neatly cut through all of issues raised by AC supplies.

An all-sample rate option is available that allows the DAC to negotiate
sample rates from CD (44.1kHz), DAT (48kHz),a and DVD-A (88.2, 96, 176.4 and
192kHz). A couple of toggle switches are used to select the actual sample rate.
The Attraction DAC is said to be the world's only digital playback machine with
static non-oversampling DA conversion up to 192 kHz. Needless to say, the
receiver-chip used (Altmann R16) is not a garden-variety off the shelf design.
Altmann explains that he had to use a custom design realized with a Xilinx
programmable logic chip, as no "useful" receiver chip for 192kHz is
available from either Crystal (Cirrus) or from AKM Semiconductor. The digital
input signals are recovered with extremely low jitter as they are generated by
custom (Golledge, UK) voltage-controlled crystal-oscillators (VCXOs) and employ
AMMís proprietary UPCI (Ultra Precision Clock Injection) technology.

Yet another DAC option is Altmannís Jitter Scrambling Decorrelator (JISCO),
which may be switched in or out. The JISCO is also available as a stand-alone
device that is said to improve sound quality even with the cheapest CD or DVD-A
player transports. The goal of the JISCO is to reduce jitter at the input to the
DAC chip by manipulating jitter before the digital data stream is processed by
an off-the shelf-receiver chip (e.g., one of the ubiquitous Crystal chips). It
accomplishes that paradoxically by actually increasing jitter at its output.
After getting through the scrambling algorithms, jitter below 10kHz is shifted
to a frequency range of several MHz where the receiver chipís internal clock
extraction PLL is most effective in reducing jitter. According to Charles
Altmann, jitter attenuation of the CS8414 is quite good at 1MHz and above, but
poor below 10kHz where much jitter is produced in CD playback. So when all is
said and done, the actual jitter at the DAC chips is lowered and uncorrelated
with the signal.

The DAC chip used is our old friend, the Philips TDA1543. Altmann is also a
firm believer in the Burr-Brown OPA134 operational amplifier because "I am good
at getting the best sound out of them. There are many other op amps available,
also much more expensive ones, but the ones I have tried out just don't have
that "134-sound". A total of five of these devices are used per
channel: one for current to voltage conversion and four as an output buffer. The
OPA134 has been around for a while and according to Burr-Brown features a true
FET input stage and increased headroom to provide superior sound quality and
speed for audio applications. Note that the Attraction DAC does not
invert signal polarity.

For the record, my review sample was configured as follows: the Attraction
DAC (base price of Ä750) with the all-sample rate option (Ä250), and the
JISCO option (Ä250) for a total cost of Ä1250. Prices and options are
spelled out at www.mother-of-tone.com.

The Truth Changes EverythingThe Attraction DAC changes everything. Attraction=Revelation. Its level of
performance is so superior to that of other DACs in the under $3,000 price point
that it simply obliterates the competition. In fact, upon further review, I have
to admit that the Attraction DAC has given me the best CD sound I have
experienced in the past 25 years... cost no object. No, I have not heard every
DAC or CD player out there, so I am not proclaiming it as the best there is,
just that it is a fantastic performer in every important musical aspect.

Audio critics, on the whole, tend to magnify small differences between
competing components. At the highest levels of high-end audio such differences
become elusive, and in some cases may well be a function of system and room
interactions. With this DAC, the differences were obvious and dramatic. The
impression of clarity was immediately startling in its diamond-like precision.
There was simply no veiling of the musical fabric. Low-level detail was
resolvable as if peering into the soundstage via a high-powered microscope. This
was no cheap trick achieved by brightening or etching harmonic textures. Many
speakers have sold in the showroom on the basis of a presence region boost or
high-frequency emphasis. Such a tonal balance is most impressive, at least in
the short run, but rather fatiguing as most consumers discover to their dismay
much later. In this case, detail resolution was a function of pristine, pure
harmonic textures free of digital artifacts, so that the auditory system had an
easier time unscrambling and resolving the various instrumental lines. Vocals,
laced in EQ and artificial reverb (standard protocol on pop multi-track
recordings), that would turn "corrosive" on most DACs were reproduced with the
full splendor intended by the recording engineer. You should really hear the
expansion and decay of reverb through this DAC. Absolutely breathtaking! I am
not suggesting that I was inundated with detail. Much like observing a school of
fish in an aquarium, most of the time it was the ensemble that captured my
attention, but it was always possible to focus on an individual and follow its
explicit movements.

The tension generated by microdynamic nuances and transient attack was left
fully intact. Transients were unfolded with racing-car speed and dynamic
conviction. On the flip side, decay of musical lines was preserved down to a
velvety black background. Couple that with a soundstage of immense transparency.
It felt as though a giant searchlight had illuminated the inner recesses of the
soundstage. Depth and width perspectives were fully fleshed out. Image outlines
were laser sharp, so that it took no effort to resolve the ebb and flow of
individual instruments within the musical tapestry. The Gestalt of listening to
a cohesive musical ensemble, in the same place at the same time, usually a
strength of analog sound, was much in evidence.

Above all else, the music possessed both body and soul. The musicís full
palette of emotions was propelled forward with verve, from a whisper to a
scream, from a sweet refrain to a touch of the blues Ė a veritable "soul train"
of emotions. This is not the sort of DAC that will ever put you to sleep.
Audiophile obsession with detail and imaging is akin to mental masturbation.
Thatís no way to reach a sonic orgasm. Fidelity to the real thing starts with
timbre accuracy, and this was an area that the Attraction DAC excelled in. The
corpus of each instrument was portrayed with a believable foundation and a
purity of harmonic texture. Bass lines were full, tight, and in time with the
upper octaves. The midrange with associated tube amplification was slightly rich
and warm, which is the way I like it. My guess, as I have yet to pin this down,
is that this rich and dark disposition is not intrinsic to the DAC but a
reflection of the character of the associated tube gear.

Bottom line: It should be clear that the Attraction DAC pushed all of
my buttons. Anyone serious about music needs to audition this DAC. It will
redefine your expectations of what is possible with the standard CD format. What
a enjoyable way to rediscover your CD collection. Simply put: a tour de force of
digital design!